Tyre Change Due

[BigPete]

Well looks like I've got to change my tyres - again. :yuk:

 

Last time I put the 10 ply Trello's on and was in such a hurry to get back in the air I didn't machine the rims as most people seem to recommend.

 

So now I'm thinkin' I have a real of a job in front of me. :ah_oh: One good thing about the 10 plys - the sidewalls are so stiff that even when flat as a tack you can still move the aeroplane. :thumb_up: And I recon you'd land OK too.

 

Any words of wisdom before I start (I plan to remove wheels and bring them home to my shed (extra tools)). :big_grin:And a real BIG hammer.

 

regards

 

:big_grin::big_grin:

 

 

[Captain]

Pete,

 

If you know somebody who races Go-karts or you know the local kart store, it might be worth borrowing a kart tyre bead breaker as their wheels are similar dia.

 

My 10 plys went on and off quite well, but if they are stuck, an angle grinder might be good to cut the cords around the bead.

 

Let us know how you go.

 

Will you have the new rubber tyre blacked for your grand (re)entrance @ Temora?

 

Regards Geoff

 

 

[flie43]

Hey Pete, I was thinking of going 10 ply next. What is with machining the rims- this is the first time I have heard that ??

 

Terry

 

 

[BigPete]

G'day Geoff, my new tyres will be so new :thumb_up: they won't need blackening! :big_grin: An angle grinder may just be my best bet.

 

G'day Terry, even the standard (Jabiru) 6 ply tyres can be a right sod to get off the rim :yuk: (very, very tight). An L2 I know (tons of Jabiru experience ) advised me to take "a little" off the inside of the rims to make future removals easier. (I didn't do it as I was in a hurry to go flyin')

 

I think I'm in for a tough time. :loopy:thumb_down:censored:

 

regards

 

:big_grin::big_grin:

 

 

[Tomo]

So what's the problem? Is it breaking the bead?

 

Just put it in your vice, does the job beautifully (if the jaws open wide enough)

 

if you don't have a vice, or doesn't open wide enough, try a "F" clamp, or even a "G" clamp would do. Put it as close to the rim as possible, and clamp it up till it pulls it off the rim, do that in a few places, and you'll be laughing.

 

There are quite a few more agricultural ways of doing it, but the above should do the trick. If you're going to start destroying it with a grinder, you can also drill holes in the tyre, (as close to the rim as practical) in 3 or 4 places around it, and put bolts through with flat washes either side. Bolt it together and you'll pull the tyre away from the rim.

 

Anyway, I'm getting carried away again.:pc strikes back:

 

 

[BigPete]

Yes - Yes - YES - TOMO

 

Did all of that last time :yuk: - you can only get so close to the bead without destroying the rim. Rubber is very bendy stuff and the clamps just slip off (and I can't get the jaws of the vice close enough to pull off the bead from the rim). and double .

 

ITS NOT FUN.

 

However - your holes and bolts idea may have some merit. i_dunno:thumb_up::big_grin:

 

regards

 

:big_grin::big_grin:

 

 

[GraemeK]

It's a bit pricey just for use on the Jab I guess, but I use Tyrepliers bead breakers on my 4WD.

 

They handle 13" to 19" rims, and mine came with a 4" to 12" adaptor so it'd do the job.

 

Work like a charm, and won't damage tyres or rim!

 

EDIT: Just checked out their website, and they have a lightweight motorcycle bead breaker for around $80 that should do the job (just like a fancy G-cramp but won't slip off) - but I reckon markendee's suggestion is the go!

 

 

[markendee]

Or .................... you could take the wheels to your mate just east of you and use the bead breaker on the tyre changer at his motorbike shop.

 

 

[BigPete]

Thanks Graemek - they are pricey, but has given me a few idea's.......

 

regards

 

 

[BigPete]

Geez Mark - you're a champion. Why didn't I think of that. Is tomorrow too soon?

 

regards

 

 

[Tomo]

Ok Ok Ok.... :thumb_up: You could make up an adapter for your vice. ;) (if you had a welder, some steel rod, and a bit of angle line :DevilDog: ) And a tiny bit of an imagination i_dunno

 

For breaking truck tyre beads out in the middle of no where, (or west of elsewhere ) we use a slide hammer thingo, looks a bit like a crow bar, but the tip is more like a tyre lever type bend on it, (and smooth edges ). Seems to work pretty good, (a bit time consuming, but great for the stomach muscles )

 

Machining the rim's sounds a bit... ify :black_eye: ... but I guess they're only there to make the aircraft roll easier, not like it's traveling a million miles.

 

 

[Tomo]

motorcycle bead breaker[/url] for around $80 that should do the job (just like a fancy G-cramp but won't slip off) - but I reckon markendee's suggestion is the go!

There you go, got the design there for you... would only take 5 mins to nock something up for your F clamp. :thumb_up:

 

Though Marks suggestion is definitely worth a high rate of consideration, but think if you had one for next time eh?! :thumb_up::thumb_up:

 

:big_grin::big_grin:

 

 

[markendee]

Epic Pietro,

 

Tomorrow is good. Had the exact same problem with the original tyres on GR's Savvy when he decided to replace them with Tundra tyres. He (as you know) is pretty resourceful and tried every which way and then some to get them off.

 

When he finally gave up and listened to his little mate we took them off at the shop.

 

A mate of ours has a machine shop here and while they are devoid of rubber perhaps you could take CB's advice and have a "little bit" machined off them.

 

A tick in every box!

 

Mark

 

 

[BigPete]

OK Mark I'll be there (around 9.30) and I'll bring morning tea :thumb_up: (for the guys (and gals)) with me. :big_grin:

 

Tomo - thanks for the links :thumb_up: - I do appreciate your support and encouragement. :big_grin:

 

(Maybe we should hold a competition at Temora Natfly and see who can change a Jabiru tyre (equipped with a boy scout pocket knife, rusty philips head screwdriver and one metre of dental floss ) in the shortest time. Sometimes I can't help myself.

 

regards

 

:big_grin::big_grin:

 

 

[Tomo]

No worries boss... 'tis a pleasure

 

Though I would be a liar if I take credit for the links, 'cause Graham gave you them :thumb_up:

 

Look forward to seeing you at Natfly, though it's concerning me who's Jab is going to have the flat tyre??? Maybe I should bring my guard dog... to keep away fiddling fingers...

 

 

[BigPete]

Yes, you're right (again) Tomo :thumb_up: - many thanks Graham.

 

I've just returned from the airport with two Jabiru rims in need of a tyre change. :ah_oh: Why do I think that was the easy bit. :yuk:

 

regards

 

:big_grin::big_grin:

 

 

[Dieselten]

Before I start, these remarks apply to J160/230-size tyres.

 

Jabiru advise the use of "tyre-bead lubricant" for changing tyres. Because I am too lazy to go and find some at an auto accessories shop, I made mine using Lux flakes in a jam-jar with enough water to make them into a thick, pasty mash, about the consistency of soap that's been left in water just a fraction too long. Apply generously to inside of tyre-bead and inside of rim with a stiff-bristle paintbrush (a 25mm or 1-inch brush is fine) and it makes the job of getting new tyres on and off (when worn out) a lot easier! Believe me, this actually works!

 

BTW, Lux is mild and won't corrode the aluminium rim. Been using this trick for the last 2 years, and I have changed at least a dozen Jabiru tyres on my J160C in that time, plus a few on other Jabs locally. Taxying on highly-abrasive paved taxiways eats up tyres!

 

Some other tips:- slightly inflate the tube to make sure it fits well inside the tyre casing before buttoning up the rims tight. This avoids pinching part of the tube between the rims. About 2psi is all you need. Try using talcum-powder inside the tyre-casing to assist the tube to settle evenly. You can put the tube insude the tyre-casing and slightly inflate it before putting the hub-halves back in, just be sure to orient the tube so the valve-stem is on the correct side so it comes out the hole in the hub!

 

The disc rotors are easy to bend! If you stand on the tyre to break the bead, BE CAREFUL NOT TO BEND THEM! (If your brakes shudder, you bent your disc-rotor.) For a tyre-change, there is no need to remove them, just use deep sockets to gain access to the hub-bolts and nuts. "Tyrepliers" work reasonably well, but a motorcycle-tyre bead-breaker is a good investment if you are going to be regularly changing Jab tyres.

 

You can re-use the Nyloc nuts as long as the Nyloc section still retains a grip on the threads.

 

I use a long "Pearl-catch" to re-insert the bolts through the holes in the hubs because with the disc-rotor attached your fingers can't get deep enough to insert the bolts. A deep 7/16" socket and T-handle is perfect for tightening the hub-bolts (from the head) with the nuts on the outside of the wheel. Hold the nuts still with a 7/16" ring-spanner from the Jab kit.

 

Break the bead on the disc-side first! Once it is broken, remove it, leaving the tyre with just the other half of the hub attached. You can often remove the tyre from the other half with your fingers. If you need to stand on it to break the bead, at least there is no disc to bend.

 

If your tubes are older than 12 months, replace them too! They perish when they get old and burst at the most inconvenient times. Tubes are cheap. Keep them on hand. A lot of flat-tyres are due to tubes spontaneously perishing and letting go when the tyre-casing is perfectly intact, with no penetration by a sharp object.

 

When you remove a wheel, clean up around the disk-brakes and the axle. Remove and clean the axle-spacer shim (right inside the wheel, hard up against the end of the stub-axle). Grease the axle with a good high-pressure grease. Clean and re-grease the inside of the wheel-bearings too. It stops the bearings seizing onto the axle and makes getting the wheel back on a good deal easier. Use a rag and clean the accumulated dirt off the bearing-seals as well. When you are finished cleaning there should be a lot of dirt on your hands and the rag, and none on the bearing-seals, bearing inner-surfaces and axles. Don't forget to replace the spacer-shim (if fitted) in the correct orientation.

 

If your J160/J230 is kit-built, consider leaving the springs off the bolts between the calipers - it makes re-assembly much easier, and the brakes still work just fine. If it's factory-built, you have no choice - the springs have to go back on.

 

Re the brake-pads. The captive-nuts tend to fall out. I use a dab of orange high-temp silicone to hold them in place in slot in the pad-holder. This is flexible enough to allow the nut to move a little to align with the bolt when you re-assemble the brakes, and stops the nut falling out completely and getting lost. Clean the pad-holders and apply the Permatex goo, let it skin over and re-assemble the brakes. (Why Jabiru didn't use a Nutsert instead of semi-captive nuts escapes me.)

 

If you bend your discs, they can be flattened with a hydraulic-press, or judicious blows from a "dead-blow" hammer on a good, flat surface. If you have "wavy" discs, the tabs are the bits that bend. Look along the edge of the disc to see where the bend is. You'll see it soon enough. If your discs are badly pitted, replace them because pitted discs will chew out a new set of pads in record time. Remember, disk-brake rotors are made of the cheapest steel available on the "no expense is spared to keep the cost down" principle.

 

Jacking the Jabiru can be done with a wooden T-shaped prop that you slide under the wing, or for the curved undercarriage on the 160/230 series, a vehicle scissor-jack under the base of the leg works well, but just watch for interference from the body of the jack with the brake-disc.

 

I counter this my lifting the wingtip up on the side I am going to jack up to allow the leg to spring inwards before applying the jack. The wheel can move in quite significantly once you take to load off the undercarriage-leg. You don't want this to happen whilst the aircraft is on the jack!

 

If you can't get the small bolt that holds the J160/230 wheel-retainer piece on back through the hole, the wheel isn't fully on the axle. Don't force it, find out why and fix the problem. The little bolt will drop through the hole once the wheel is fully on the axle. Don't forget to put the washer and nut back on and tighten them!

 

The most useful thing I ever got from the Jabiru manual on tyre-changing was the bead-lubricant tip. It really does work. The rest of the stuff above comes from experience.

 

One last thing: when your tyre-change turns pear-shaped, remember "oaths in anguish rank with prayers".

 

 

[BigPete]

OK girls and boys - thought I'd better let you all know how it all went. i_dunno

 

Arrived at Marks, and after a few pleasentries :big_grin: got down to it.

 

We decided to remove disc brake rotors from the rims before attempting to remove tyres. :thumb_up:

 

Used the small tyre remover machine which generally does the ride on mower tyres.

 

Worked a treat, loosened the beads sufficiantly to remove bolts and split the rims (with a bit of wriggling and jiggling). :big_grin:

 

Bolted rims back together and shot around the corner to a mates machine shop and had him remove 1mm of the inside and outside of each rim.

 

(A 2mm dia reduction).

 

Said "thanks very much" paid him way too little (he wouldn't take anymore) and returned to say thanks to Mark and the Crew (I knew Mark would be insulted if I tried to pay him, so I left some light refreshment instead. :thumb_up: You're a champion bloke Mark (like most Recreational Flyers).

 

Got home and started to re-assemble the wheels. Separated the rims once again, taking care to mark the halves so they would go back the same way. Bolted on the rotors, and lubricated the tyre with liquid hand soap - worked a treat. (thanks Dieselten) Pushed the rear rim into the tyre - still a snug fit but after standing on the rim (not the rotor) it went in all the way. :thumb_up:

 

Flipped it over and inserted a new tube into the tyre, and hand pumped to partially inflate so as not to pinch the tube when inserting the other rim. Lubricate tyre bead, outside rim still a tight fit, but nothing like it would have been if not machined. :thumb_up:

 

Found a couple of 1/4" x 4" bolts with nice long threads - packed it with spacers and washers and pulled both halves of the rims together (very easy) so I could insert the original bolts. Presto - one tyre ready to go. :big_grin:

 

Ditto second wheel. :big_grin:

 

All done and dusted, Jabiru ready to go. :thumb_up:

 

Thanks to all who contributed on this thread. Big thankyou to Mark.

 

regards

 

:big_grin::big_grin:

 

 

[Tomo]

Good work Pete... specially for a horn blower....